Critics praised "Human Behaviour" and deemed it a highlight of the album. The song was an underground smash, which peaked at number two on the dance charts[2] and reached number 36 in the UK Singles Chart.

The music video was directed by Michel Gondry and is the first time the two collaborated. The video, as the song, is a story about the relation between humans and animals, from the animal point of view.[1]

"After The Sugarcubes, I guess I had a mixture of liberation and fear. It had been obvious for a while in the band that I had different tastes than the rest. That's fair enough - there's no such thing as correct taste. I wrote the melody for "Human Behaviour" as a kid. A lot of the melodies on Debut I wrote as a teenager and put aside because I was in punk bands and they weren't punk. The lyric is almost like a child's point of view and the video that I did with Michel Gondry was based on childhood memories."

"Human Behaviour" was written by Nellee Hooper and Björk, and was produced by Hooper. The song was first written in 1988[4] when Björk was still the leading singer of The Sugarcubes, but she decided not to release it with the band.

The song was inspired by David Attenborough documentaries and by the relation between humans and animals. Björk explained to Rolling Stone, talking about the inspiration for the song: "'Human Behaviour' is an animal's point of view on humans. And the animals are definitely supposed to win in the end."[3] On a recent question and answer session with fans on The Guardian website, Björk revealed more information about the writing of the song: "I wrote it I was referring to my childhood and probably talking about how I felt more comfortable on my own walking outside singing and stuff than hanging out with humans..."[5]

This is the first song on the "Isobel song cycle", a transcendental cycle in Björk's discography which goes from "Human Behaviour" to "Wanderlust" (2007).

The B-side contained in the cassette edition of the single is the reggae-influenced "Atlantic", which was produced and written by Björk. Its lyrics talks about Björk's family: "My son has eight grandmothers and eight grandfathers and it's about the love and the complications of that".[3]

The song opens with sounds of drums and snapping, during the second verse a bass is heard. Björk sings the bridge accompanied by strings. The song continues with a keyboard solo and finishes as Björk sings "There's definitely, definitely, definitely no logic/Human..."

In the album version, as the song fades out, the second track "Crying" begins.

"When we did our first video, for "Human Behaviour", I was thinking: "Great, we're going to Iceland and we're going to shoot a lot of great landscape." And she [Björk] said no - she had a similar idea as my friend Etienne in Oui Oui, she wanted to use animals to reflect human nature. And it was great, because as soon as she started to throw some ideas, they started to bounce in my mind and imagination and I immediately came back with other ideas, and we did a video that was very collaborative. "

"'Human Behaviour' is an animal's point of view on humans. And the animals are definitely supposed to win in the end. So why, one might ask, is the conquering bear presented as a man-made toy? I don't know. I guess I just didn't think it would be fair to force an animal to act in a video. I mean, that would be an extension of what I'm against. I told him [Gondry], 'I want a bear and textures like handmade wood and leaves and earth, and I want it to seem like animation.' Then I backed out."[3]

As the video starts, a car approaches a hedgehog while the animal tries to cross a country road. Images of a toy-made bear approaching a hunter in a threatening way are shown. As Björk starts to sing, she appears in hut, sit at a table, seemingly eating something. Meanwhile, in the forest, the hedgehog manages not to get hit by the car and approaches the hunter, who's now lying on the ground.

As Björk sings, she appears walking in the forest, seemingly followed by the bear. A frame shows a nest full of Björk-like humans trapped in a pupa. When the bear and the singer meet, the animal roars at her and she starts to fly through the forest, and during the flight she cling to a tree, but as the tree collapses, she falls down near the Hunter, who's still on the ground, and she appears having the same dimensions of the hedgehog. Then, the situation of the first frames is repeated, as Björk tries to cross the road and manages not to get hit by the car, driven by the Bear. In the following scenes, she sings in a water flow in the middle of the forest. While she contemplates the sky, the Moon appears to emanate pulsations, and on the satellite, the singer is shown dressed as an astronaut, while she's planting a Soviet flag.

Björk appears to fall down from the Moon, and seemingly falls down in the Bear's throat, however she keeps singing even in the animal's stomach. During the breakdown, she dances in her hut tapping and looking at a bulb, while a moth falls down in her plate. Scenes of the bear attacking and dragging the hunter are shown. As the video fades out, the singer continues singing in the stomach of the animal.

The video was well received by music critics, which complimented its originality. Critics praised also the chemistry between Gondry and Björk: "The imagery of 'Human Behaviour' is a web of various physical, in-camera effects that Gondry uses throughout his film career. Models, composites, screen projections (all featured in image eight), and lighting (see image two) abound in Björk's emotional woodlands. Colors are deep and saturated. In addition to his unique perceptions of Björk's music, Gondry's art of storytelling are unique to the music video world. 'Human Behaviour' is a story of predator and prey. In search of food, a bear clomps through a forest in the evening. A rugged hunter stalks the woods in pursuit of his game. Björk, as narrator and character(s) of her own story, flees from the bear. Numerous times the bear almost succeeds: in one attempt he drives a car, and almost hits Björk. In the end, Björk flies down the throat of the bear, and rests in his stomach. The hunter also meets his demise. The video is a classic; a vivid story rendered in Gondry and Björk's surreal playground."[3]

In 1993, Rolling Stone included the Music Video in The Top 100 Music Video of all Time list, at number 96.[9]

The song was well received by music critics. For AllMusic's Heather Pares, the song's "dramatic percussion provides a perfect showcase for her wide-ranging voice".[12] The New York Times described the lyrics of "Human Behaviour" as a "parallel between the beastliness of humanity and the bestiality of nature.[13]

The song was parodied on the PBS show Bill Nye the Science Guy as "Cross Pollination," with lyrics concerning plants. Although the original vocal melody was not used, the music is unmistakably an attempt to spoof the backing of "Human Behaviour".

Björk promoted the song by a series of TV appearances. She performed the song and "Big Time Sensuality" on MTV's Most Wanted while dressed in a pink skirt and yellow tee, accompanied by an Hammond Organ and Tablas.[15] On 13 October 1993 she performed a set of three songs, including "Come to Me" and "The Anchor Song" on Planeta Rock.[16] The song was part of her MTV Unplugged setlist, and was performed with a harpsichord solely. At the 1994 Roskilde Festival, Björk joined Underworld on stage to perform the Underworld remix of the song.[17]

Björk performed the song in all of her tour. During the Vespertine World Tour, the song featured a more electronic arrangement accompanied by a more classical Orchestra. During the Volta Tour, the song was performed only once [18] and featured a brass arrangement.